The present invention relates to an actuator apparatus, process of forming thereof, and method of actuation, and in particular, this disclosure provides an electrostatic actuator apparatus, process, and method of electrostatic actuation.
In general an actuator can be defined as a mechanism that causes a device to be turned on or off, adjusted or moved by converting various types of energies such as electric energy or chemical energy into kinematic energy. Small scale (i.e., miniature) actuators are referred to as micro-actuators. Actuators with a microstructure are often formed using semiconductor processing
Different types of actuators are categorized by the manner in which energy is converted. For instance, electrostatic actuators convert electrostatic forces into mechanical forces. Piezoelectric actuators use piezoelectric material to generate kinematic energy. Electromagnetic actuators convert electromagnetic forces into kinematic energy using a magnet and coil windings.
Electrostatic actuators are used in micro-electromechanical systems (MEMS) for producing fine positional adjustments. For instance, micro actuators are known to be employed in ink jet heads for ink jet printers.
The present invention relates to an electrostatic actuator apparatus, process of forming thereof, and method.
According to one embodiment of the actuator apparatus an apparatus includes first and second spaced apart substrates. The first substrate has a first surface including a first electrode and the second substrate has a second surface that opposes the first surface and includes a second electrode. A flexible member is positioned between the first and second surfaces. The flexible member has a first member surface positioned opposite to the first surface and a second member surface positioned opposite to the second surface. A first distal end of the flexible member is fixedly attached to the first surface and a second distal end of the flexible member is fixedly attached to the second surface. A third electrode is formed on the first member surface and is positioned opposite to the first electrode. A fourth electrode is formed on the second member surface and is positioned opposite to the second electrode.
During a first operative cycle the third electrode portion is charged thereby causing the third electrode to be drawn towards the first surface resulting in a first movement of the member and in a second operative cycle the third electrode is discharged. During a second operative cycle the fourth electrode portion is charged thereby causing the fourth electrode to be drawn towards the second surface resulting in a second movement of the member and in the first operative cycle the fourth electrode is discharged.
According to one embodiment of the present invention a method of actuation is performed by initially providing first and second spaced apart substrates that have first and second opposing surfaces, respectively, where each surface has a first electrode and a second electrode, respectively. In addition, a flexible member is provided that is positioned between the surfaces and having a first member surface positioned opposite to the first surface and a second member surface positioned opposite to the second surface, in which the flexible member has a first distal end fixedly attached to the first surface and having a second distal end fixedly attached to the second surface is provided. A third electrode formed on the first member surface and positioned opposite to the first electrode and a fourth electrode formed on the second member surface and positioned opposite to the second electrode.
During a first operative cycle, the third electrode portion is charged and the first electrode is oppositely charged such that the third electrode is drawn towards the first surface resulting in a first movement of the member. In a second operative cycle the third electrode is discharged.
During a second operative cycle, the fourth electrode portion is charged and the second electrode is oppositely charged such that the fourth electrode is drawn towards the second surface resulting in a second movement of the member. In the first operative cycle, the fourth electrode is discharged.